Piston packing-ring.



C. L. SHEPHARD.

PISTON PACKING RING.

APPLICATION FiLED AUG-3. 1914.

1,175,383. Patented Mar. 14,1916.

ain spawns earners oeu re GLARENGE L. SHEPI-IARD, 0F ILIOUIS, 'MISSOURI,ASSIGNGR TG BUFFUM T002 COMPANY, OF LOUISIANA, MISSOURI, A CORPORATIONOF MISSOURI.

PISTON PACKING-RING.

Specification of Letters IPatent.

Patented Mar. is, rare.

ing is a full, clear, and exact description, I such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to piston packing rings, and has for its mainobject to provide a piston ring that is constructed in such a mannerthat it effectually prevents leakage between the cylinder. wall and thepiston with which the ring is used.

Another object is to provide a piston ring that is composed. of aplurality of separate annular sections which cooperate with each otherso that different sections are automatically-brought into intimatecontact with the wall of the cylinder at certain times during the strokeof the piston.

Other objects and desirable features of my invention will be hereinafterpointed out.

Figure 1 of the drawings is a vertical sectional view of a portion of anengine cyl' inder, showing the piston in elevation and equipped withapacking ring constructed in accordance with my invention. Fig. 2 is atransverse sectional view of the packing ring, the parts comprising samebeing slightly separated. Fig. 3 is a detail sectional view illustratingthe approximate po-.

sition assumed by the several parts of the ring when the piston withwhich it is used is at rest. Figs. 4 and 5 are detail views similar toFig. 3, illustrating the approximate position assumed -by the severalparts of the ring when the piston is moving upwardly and downwardly,respectively; and Fig. 6 is a detail View similar to Fig. 3,illustrating a slightly modified form of my invention.

Briefly described, my invention consists in forming a piston packingring of a plurality of separate ring-shaped expansible members, thecentral or inner member being provided with means that coiiperates withmeans on the other members, so as to force one or the other of the sameinto engagement with the cylinder wall at certain times during thestroke of the piston.

- Referring to Figs. 1 to 5 of the drawings,

which illustrate the preferred form of my invention, A designates apiston that is reciprocatingly mounted in a cylinder B, and C designatesmy improved packing ring that s arranged in an annular groove D formedin the piston A. The ring O is composed of a central or body portion 1and upper and lower portions 2 and 3', respectively, all of saidportions being preferably in the form of split expansion rings. Thewidth of the central portion 1 at the inner face thereof isapproximately equal to the width of the groove D, and said portion isprovided with a lateral extension or flange that is beveled or inclinedon its upper and lower faces, said beveled surfaces extending to andterminating at a point adjacent to the center of the outer face thereof,where a pair of horizontally disposed annular shoulders or abutments 4is formed. The portions 2 and 3 of "the packing ring are alike andinterchangeable, each of said portions being provided with a Hathorizontally disposed surface that cooperates with one of the horizontalwalls of the groove 1), a. flat vertical surfacethat cooperates with thewall of the cylinder and a. beveled or inclined surface that cc operateswith one of the beveled surfaces on the portion 1, so that when the.ring G is assembled, the relationship of the several portions is asshown in Fig. 3.

By referring to Fig. 3 it will be noted that the groove D in the pistonA is slightly deeper than the portion 1 of the ring, and that thecombined widths of the outer faces of the upper and lower portions 2 and3 ing ring is used is at rest, the several parts of said ring lieapproximately as shown in Fig. 3, wherein the inner face of the portion1 is spaced away slightly from the vertical wall of the groove-D and thehorizontal faces of the upper and lower portions 2 and 3 are out ofcontact with the horizontal walls of said groove and the horizontalshoulders or abutments 4s, on the ring 1. When the piston movesupwardly, the portions of the ring assume the position shown in Fig. 4,wherein the friction on the side wall of the cylinder 13 has forced theportion 2 downwardly against theportion 1, the cotiperating beveledsurfaces on said portions causing the portion 1 to be forced inwardly,so as to snugly engage the vertical wall of the ioo groove 1), and theportion 2 to be forced outwardly against the cylinder wall, the

abutment or shoulder at limiting the lateral beingspaced away from theportion 1 and engaging the cylinder wall comparatively lightly, due toits own expansion only. It will thus be seen that on the upstroke of thepiston the portion-2 is positively forced outwardly into intimateengagement with the wall of the cylinder, thus absolutely preventing theescape of gas between the cylinder wall and piston, and the portion 1 ispositively forced inwardly against the ver tical wall of the groove D,so as to prevent the escape of gas around the ring C. The portion 3 otthe ring exerts sutiicient pressure on the cylinder wall to prevent anyleakage of gas that niay pass through the open space or joint of thering 2, the joints or open spaces of all of said portions beingpreferably staggered, as shown in Fig. 1. Any suitable means may beemployed for preventing the portions of the ring from working around oneach other, so as to line up the openspaces formed therein, the

I means herein shown consisting of pins 5 in the body portion 1 thatcooperate with slots formed in the members 2 and 3.

On the downward stroke of the piston, the several parts of the ringassume the position shown in F l, wherein the portion 3 is positivelyforced outwardly against the cylinder wall and the portion 1 inwardlyagainst the vertical wall of the groove 1).

From the foregoing it will be seen that on the up and down strokes ofthe piston,

,respcctively, the portions 2 and 3 of the ring (1 are successivelybrought into intimate contact with the cylinder wall, and the portion 1'is forced inwardly against the vcrticalwall oi' the groove D,.thusetfectually preventing any leakage, either past or around the ring. C.

In Fig. 6 I have llltlStltltLXltL slightly modified form oi? myinvention, wherein the portion 1 of the ring" C is approximatelyT-shaped in cross section, the top and bot-- tom faces of the laterallyprojecting portion thereof being flat insteadoi' beveled, and theportions 2 and 3 rectangular in cross section.

From the foregoing it will be seen that I have produced a piston packingring that is more etlicient than the rings now in general use, that canbe easily applied to or removed from the piston, owing to the fact thatall the parts comprising same are in the form of split expansion rings,and which comprises few simple parts that can be manufactured cheaply.

Having thus described my invention, what I claim is: I

A piston packing ring that is adapted to he slipped over the head of thepiston of an internal combustion engine, compris= ing a centralinherently expansible split ring that is composed of an inner portionthat is approximately of the same width as the groove in which the ringis arranged, an outer portion ofless width than said groove and havingfaces that lie parallel to the side walls of said groove, the outer edgeof said outer portion normally engaging the wall of the cylinder withwhich the ring cooperates, and an intermediate portion that joins saidinner-and outer portions, the walls or said intermediate portionconverging from said inner portion to said outer portion; an inherentlyexpansible split ring arranged on each side of said central ring andprovided with an inclined surface that cooperates with the intermediateportion of said central ring, and a surface that cooperates with andlies parallel to the walls of the outer portion of said central ring;and means on said central ring that cooperates with means on each of theother rings for preventing circumferential movement of any of said ringswith respect to theot-hers. In testimony whereof I hereunto atlix mysignature in the presence ot two witnesses, this thirty-first day ofJuly, 191.4. 1

CLARENCE L. SHEPHARD.

Vi itncssesz v Wnrns 1a. Cuunon, Gnonon Bannwsnn

